Swine Nutrition

1
Swine Nutrition
2
Where are we going??

• Characterization of the swine industry
• Review of nutrient requirements and utilization
  by pigs
• Feedstuffs used in swine diets
• Feeding pigs in different stages of production
• Boars, Gestating Lactating females
• Nursery pigs
• Growing-Finishing pigs
• Factors affecting swine nutrition

3
Characterization of the Swine Industry

• Past, Present, and Future

4
The Swine Industry in the Past

• Pigs were kept as adjunct to crop production
• Add value to enterprise when crop prices low
• 1180-1940
• Consumer demand was for lard only
• Production of fat hogs
• WWIIfat hogs
• Fat used for making nitroglycerine for explosives
• Meat used as rations for soldiers in field

5
The Swine Industry in the Past

• After WWII great changes for pork industry
• Demand for lard ?
• Consumers considering diet and health more
• ? demand for leaner meat
• Early 1950s
• US pork producers concentrated their efforts on
  developing leaner hogs to meet demands for meat
  containing lower amounts of cholesterol and fat

6
The Swine Industry in the Present

• 100,000 pork producers
• Compared with 3,000,000 producers in 1950
• Farms growing in size
• 80 of hogs are grown on farms producing 1000 or
  more hogs/year
• 50 of hogs are grown on farms producing 2000 or
  more hogs/year

7
The Swine Industry in the Present

• 1980s and 1990s
• Production expanded outside Midwest
• Breeding programs were developed that resulted in
  ? reproductive efficiency and lean muscle growth
  (? feed efficiency)
• Evolution from generalized to specialized
  production schemes
• SEW
• Multi-site production
• Wean-to-finish facilities

8
The Swine Industry in the Present
9
The Swine Industry in the Present

• Feed is major production input in swine
  production systems
• 65 of total expense
• 1998
• Largest number of hogs produced/slaughtered
• 101 million animals
• 18.7 billion lbs.

10
The Swine Industry in the Present

• Annual farm sales exceed 11 billion whereas
  annual retail value of pork exceeds 30 billion
• Pork production and processing is responsible for
  over 66 billion of economic activity

11
The Swine Industry in the Future

• Legislative action regarding
• Environment
• Regulation of who may produce pork
• Where pork production can occur (location!)
• Vertical integration!!!!
• One company owns
• Pigs
• Slaughter/processing facilities
• Retail facilities

12
The Swine Industry in the Future

• Global Market!
• Pork has a 43 share of world meat protein market
• Exporting 5.6 of production in 1996
• Net exporter of pork for first time since 1952
• Industry experts discuss a scenario where 50 pork
  producers would produce majority of US product by
  2010.

13
Why study swine nutrition?

• South Dakota (2000)
• 1,600 farms with pigs
• 2.3 million market hogs/yr
• 145,000 sows
• 284,864,000 gross income

14
Why study swine nutrition?

• South Dakota (2000)
• 912,000 tons of feed
• 730,000 tons of corn
• 26 million bushels
• 182,000 tons of SBM
• 6.1 million bushels

15
Why study swine nutrition?

• South Dakota (2000)
• gt3,000 jobs at Morrells
• trucking, vet, supplies, banking, labor, buying
  stations, etc
• Swine Units are looking for good employees
• Allied industry jobs pharmaceuticals, nutrition,
  engineering, banking, etc

16
Review of Nutritional Physiology of Pigs
17
The Pig
18
Mouth

• Prehension, mastication
• Reduction in feedstuff particle size
• Begin CHO breakdown by salivary amylase

19
Monogastric Stomach
Sphincter-ingesta passage to stomach
Nonglandular region
Mucus production
Sphincter- chyme passage into SI
Produces gastric secretions
Produces mucus and enzymes
20
Stomach

• Chyme will spend 0-6 h here
• Carbohydrates
• Fermentation in young (suckling) pigs
• Lactate production (contributes to low pH of
  stomach in young pigs)
• Action of salivary amylase stopped here
• Optimal pH is 6.7

21
Stomach

• Protein
• HCldecreases pH of stomach contents
• Protein structure changedenaturationunfolding
  of protein for enzyme access
• Pepsinogen released by chief cells of fundic
  region
• pH-dependant conformation change to active
  proteolytic enzyme pepsin
• Enzyme binds active sites on protein and
  initiates breakdown

22
Small Intestine

• Digesta will spend 2-6 h here!
• Carbohydrates
• Principle site of soluble CHO digestion
• Secretions (bile, pancreatic juice, etc.) raise
  luminal pH to range of amylases (pH gt 5.0)
• Amylase released from pancreas
• Luminal CHO breakdown
• Disaccharides absorbed into mucosal cells which
  produced disaccharidases
• Mucosal digestion
• CHO absorbed into bloodstream as monosaccharides

23
Small Intestine

• Protein
• Luminal digestion
• Pancreatic proenzymes (trypsinogen,
  chymotrypsinogen) activated by enzyme released
  from duodenal mucosal cells
• Releases AA and peptides from protein chains
• Mucosal digestion
• Di and Tri-peptides absorbed into enterocyte and
  broken down by peptidases
• Dipeptides and AA absorbed into blood stream

24
Small Intestine

• Lipids
• Bile released from gall bladder emulsifies fat
• Lipase released from pancreas breaks down fat to
  TG
• FFA and triglycerides are absorbed in duodenum
• Water, mineral, and vitamin absorption

25
Small Intestine
26
Large Intestine

• Digesta will spend 20-38 h here!
• Water absorption
• Some mineral absorption (Na)
• Fermentation!!
• CHO to SCFA
• Proteins to odorous compounds

27
SCFA

• Short chain fatty acids
• Acetate, propionate, butyrate, and lactate
• Can account for 20 of ME requirement
• Lower luminal pH
• Decrease pathogenic bacteria colonization
• Facilitate water and mineral absorption

28
Nutrient Information
29
Water

• Amount/day
• sow litter 8 gal/hd/day
• nursery pig 1 gal/hd/day
• grow-finish pigs 3-4 gal/hd/day
• Flow rate
• nursery pigs 2 cups /minute
• grow-finish pigs 3 cups/minute

30
Energy (Lipids)

• Second most limiting nutrient to 100 lbs
• Pigs need it for all functions
• Pigs eat to meet their energy needs!
• Main sources are carbohydrates and oils/fats
• Energy density of the diet determines level of
  intake
• high energy diet reduced intake
• high fiber diet increased intake

31
Benefits of Supplemental Fat

• 1 fat improves feed efficiency by 2
• Fat additions reduce dust levels
• pigs
• people
• Less wear and tear on equipment
• Never more than 5 added fat to diet
• Problems with storing and mixing
• Rancidity

32
Protein/AA

• Pigs dont require Protein, they require Amino
  Acids
• Limiting AA vary according to feedstuffs used and
  age of pig, but in most grain-SBM diets, LYSINE
  is the first limiting AA

33
Protein/AA
Pigs will only perform to the level of the 1st
limiting AA in the diet, no matter what the
other AA levels are
34
Protein/AA

• If underfeed AA, increase in carcass fat and hurt
  feed efficiency
• If overfeed AA, no affect on carcass but hurt F/G
  , , and nutrient excretion
• Pig has to have genetic potential for higher
  levels of AA to be beneficial

35
Minerals

• MACRO-minerals MICRO-minerals
• Macros are in large amounts and are listed as
  s of the diet
• Micros or trace minerals are in small amounts -
  ppm or mg/lb

36
Macrominerals

• Calcium Phosphorus ratio important
• Somewhere between 11 21 Ca P
• Sodium
• added as salt (NaCl)

37
Microminerals

• Zinc (Zn)
• Manganese (Mn)
• Iodine (I)
• Iron (Fe)
• Copper (Cu)
• Selenium (Se)
• Se is a carcinogen but can be in diets up to 0.3
  ppm
• High in central SD

38
Minerals

• Can not depend on mineral vitamin levels in
  grain storage due to large variation and storage
  loss so supplement them
• Not all forms have the same availability
• ferrous sulfate 100 available
• ferric oxide 0 available
• Can have adequate total amounts in diet but if
  not available, will have deficiencies
• Some minerals need co-factors P, Ca, and Vit D

39
Vitamins

• Routinely add to diets
• Assume no activity in feedstuffs
• 2 types of vitamins
• fat soluble
• water soluble

40
Fat Soluble Vitamins

• Vitamin A
• Vitamin D3
• Vitamin E (tocopherol)
• Vitamin K (menadione)
• Short shelf-life (3 months)
• Negatively affected by heat, light, moisture, and
  presence of TM
• Illegal to store with farm chemicals

41
Water Soluble Vitamins

• Niacin
• Pantothenic acid
• Vitamin B12
• Riboflavin
• Choline
• Biotin
• Folic acid

42
Vitamins

• Source is critical
• Form will affect activity (IU/gram source)
• Acetate forms highest activity
• Premixes important here!!
• Mixing very small amounts (5 lbs/ton)
• Premix with SBM

43
Swine Nutrition through the Lifecycle
44
Feeding the Weaned Pig

• In the swine industry today
• Conventional weaning 17 d of age
• Off site segregated early weaning 12-14 d of
  age

45
Digestive Capacity
46
Digestive Capacity

• Young pig prior to weaning is adapted to
  digesting milk
• But, not other feedstuffs, esp. plant proteins
• Lactase is high, lipase and protease activities
  adequate to digest those components in milk

47
Digestive Capacity

• At weaning, enzyme activity is as much as 9 fold
  lower than 4 weeks post weaning
• Weaning results in 2 fold depression in activity
• Post weaning performance enhanced by ensuring
  that dietary ingredients provided at weaning are
  compatible with established pattern of enzyme
  secretion

48
Nutrient Requirements

• Energy
• 3265 kcal ME/kg
• Similar to lactating females, rapidly growing
  pigs do not consume enough energy to meet their
  needs for rapid protein deposition
• Thus, the use of complex, nutrient dense nursery
  diets
• Fat addition inappropriate, but done to improve
  pelleting characteristics (3-6)
• Poor fat digestion/utilization
• Provide energy with digestible CHO (e.g. lactose,
  glucose, sucrose)

49
Energy Requirements
50
Nutrient Requirements

• Amino Acids
• LYSINE!!
• Requirements for high health, rapidly growing
  pigs higher than NRC recommendation
• 1.75 Lysine in SEW pigs
• Evidence that other AA may be required at higher
  concentration than NRC recommends
• Met, Ile, Thr, Trp

51
Nutrient Requirements

• Amino Acids
• Good sources plasma/animal proteins, milk
  proteins
• Poor sources plant proteins
• Esp. soybean meal
• See reduced protein digestibility due to
  development of transient hypersensitivity to SBM
• Native storage globulins (glycinin and
  b-congluycinin)
• Antinutritional factors (protease inhibitors and
  lectins)

52
Nutrient Requirements

• Minerals
• Ca, P, Na, Cl, Cu, I, Fe, Mn, Se, Zn
• Typical nursery diets low in these minerals
• Vitamins
• B vitamin recommendation may be too low
• Research states high lean genotypes need 470
  more B vitamins than NRC states
• High antigen exposure results in higher B vitamin
  requirement

53
Common Feed Additives

• Antibiotics!!
• Summary of 1194 studies found AB improved gain by
  17 in weanling pigs
• University settingprobably twice that in
  commercial settings
• High lean genotypes and high antigen exposure may
  result in bigger effect of AB addition (Stahly et
  al., 1995)

54
Common Feed Additives

• Pharmacological levels of minerals
• Copper, Zinc
• Probiotics
• Organic acids
• Enzymes (mainly phytase)

55
Factors affecting Nutrient Requirements

• Weaning Age
• Earlier pigs are weaned, greater need for complex
  diet to minimize post weaning lag
• Antigen Exposure
• SEW-21 improvement in gain (due to reduced
  pathogens)
• Effect lasts-19 improvement in gain up to 56 d
  of age

56
Factors affecting Nutrient Requirements

• Sex and Genotype
• Gilts have greater growth rate even in nursery
• Gain approx. 5 faster than barrows
• No separate NRC requirements at this age
• Increased lean growth potential
• Higher lysine, P, and B vitamin requirement when
  compared to NRC recommendations (Stahly et al,
  Iowa State)

57
Feeding the Weaned Pig

• Phase feeding
• change from requiring energy dense, highly
  palatable and digestible diet to simple SBM-grain
  diet by 3-4 weeks post weaning
• Initial complex diet EXPENSIVE
• Eat so little for short period of time, so does
  not impact overall cost of production

58
Feeding the Weaned Pig
59
Why we Phase Feed
60
Why we Phase Feed
61
Feeding Growing-Finishing Pigs

• 30 to 120 kg (nursery to market)
• Considered least-complicated segment of swine
  production
• Newer, leaner genotypes and feeding strategies
  are changing this perception
• 75-80 of feed consumed by pigs is during this
  phase of production

62
Factors affecting GF Nutrition

• Genetics
• Differ in potential to deposit lean and fat
• Rate and composition of gain affects
• AA requirement
• Energy needs
• Rapid rate of lean gain ? AA needs and ? energy
  needs
• 1 kg muscle 2.23 Mcal
• 1 kg fat 10.3 Mcal

63
Factors affecting GF Nutrition

• Sex
• Gilts have higher amount of lean gain, larger
  LEA, and higher lean carcass
• Gilts are more efficient (consume less feed than
  barrows)
• Split sex feeding!
• Because barrows consume more feed and deposit
  less leanfiber may be incorporated to ? energy
  intake and ? fat accumulation

64
Factors affecting GF Nutrition

• Stage of maturity
• Expressed as daily needs, nutrient requirements
  increase with age
• BUT, when expressed as of diet, nutrient
  requirements decrease as animal ages
• Consuming more feed!!
• Phase feeding will lower feed costs without
  negatively impacting performance
• Improve nutrient retention
• Less N, P in excreta (? pollution)

65
Factors affecting GF Nutrition

• Environmental Temperature
• Digestion and metabolism generate heat
• This heat can be used to warm the body in cold
  environments
• Stimulation of FI
• Hot environments will reduce FI
• Supplemental fat!
• Dietary fiber results in more heat generation
  than do fats/oils

66
Factors affecting GF Nutrition

• Herd Health
• Hard to quantify, but pigs will gain quicker with
  higher efficiency when not subject to
  clinical/subclinical disease
• However, AB should not be used in place of good
  management practices!

67
Feed Management Considerations

• Feed wastage
• If feed is observed outside the feeder, 10 is
  being wasted
• Commercially available feeders have been found to
  have feed wastage of 1 to 34
• The selection of a good feeder and proper
  adjustment are critically important to reduce
  feed wastage
• A properly adjusted feeder has ¼ to ½ of the pan
  lightly covered with feed
• Indicating adequate flow rate of feed

68
Feed Management Considerations

• Ca and P
• Increased pressure concerning pollution
• Reduction of Ca and P in last 4-6 wk of finishing
  period
• Less Ca and P excretion w/o negatively impacting
  production
• Use of Phytase enzyme (300 to 500 units/kg feed)
  improves P utilization from diet 5
• Decrease amount of total P in diet and reduces P
  excretion

69
Feed Management Considerations

• Specialty Grains
• High oil corn
• 2-4 additional oil
• Higher ME when diets contain HOC
• Slightly faster gains and improved feed
  efficiency
• Esp. in the summer months
• Low phytic acid corn
• Lower phytatehigher plant P availability
• Diets formulated with less P and results in
  35-50 reduction in P excretion

70
Feed Management Considerations

• Feed Additives
• Antibiotics
• Used as growth promotants for past 40 yr
• Improve gain and efficiency
• Probiotics
• Pharmacological levels of Cu

71
Feed Management Considerations

• Feed Processing and Pelleting
• Reducing particle size (1000 to 400 1200 to 600
  microns) improves DM and N digestibility 5-20
• Finer grind simpler way to reduce swine waste
  concentration
• Industry avg. 1100 microns, but ideal is
  approximately 650 microns
• Grinding too fine can result in ulcers

72
Feed Management Considerations

• Feed Processing and Pelleting
• Pelleting is more efficacious in the nursery
  phase (more fines in those diets)
• Have seen improvements of 5 in FE
• Slight improvements in digestibility (related to
  starch fraction)
• Slightly less feed wastage observed
• Increases cost of feed

73
Feeding Developing Gilts

• Goal To optimize reproductive productivity and
  longevity

74
Feeding Developing Gilts

• Body Condition
• High culling rate of gilts due to anestrus is
  highly correlated with low body fat stores
• Due to combined effects of genetic selection for
  leanness and earlier mating, gilts enter
  reproductive portion of life with lower fat
  stores
• gt20 mm BF 46 reaching parity 4
• lt14 mm BF 28 reaching parity 4

75
Feeding Developing Gilts

• Body Condition
• High culling rate of gilts due to anestrus is
  highly correlated with low body fat stores
• This does not mean feed your gilts to obesity
• Studies show that a feeding level of 2.5 times
  maintenance or higher will result in decreased
  reproductive performance

76
Feeding Developing Gilts

• Locomotor failure
• 12 of females are culled for this reason
• Structural soundness is critical for longevity
• Significantly higher leg disorders were observed
  in females fed at levels higher than required for
  maintenance/moderate growth

77
Feeding Developing Gilts

• Practical feeding recommendations
• Nutrient needs of replacement gilts is similar to
  that of GF pigs
• Moderate restriction of FI in late
  finishing/pre-breeding to slow growth seems most
  prudent
• 110-120 kg at mating at second estrus
• Use of low energy (high fiber) ingredients to
  dilute energy content of diet
• NO recommendation for feeding the replacement
  gilt
• Too much fat locomotor problems
• Not enough fat reduced productivity

78
Feeding Developing Gilts

• Occurrence of Puberty
• 200 to 220 d of age
• Range 102-350 d of age
• Factors affecting
• Genetic line
• Social environment
• Season
• Boar exposure
• Growth rate
• Body composition
• Age

79
Feeding Developing Gilts

• Occurrence of Puberty
• 2 fold theory
• 1. Gilts must achieve a certain body composition
  before they will exhibit first estrus
• Frisch, 1988 showed girls would not cycle until
  reaching a certain level of body fatness
• Armstrong and Britt, 1987 reported similar
  correlation with gilts and BF suggesting
  cessation and resumption of estrus cycles occur
  at different body compositions

80
Feeding Developing Gilts

• Occurrence of Puberty
• 2 fold theory
• 2. Chronological age affects onset of puberty
• As gilts achieve a certain age they are developed
  enough to begin cycling
• Most scientists believe onset of puberty is a
  combination of these 2 theories

81
Feeding Developing Gilts

• Dietary Nutrient Supply the Occurrence of
  Puberty
• Review of literature in 1985 found that severely
  overfeeding or underfeeding gilts will delay
  puberty, but to what extent is unclear
• Researchers have reported that restricting
  protein and/or energy intake from 30-100 kg can
  delay onset of puberty

82
Feeding Developing Gilts

• Dietary Nutrient Supply the Occurrence of
  Puberty
• Thus it has been suggested that gilts be fed for
  rapid growth during the rearing period to
  encourage early expression of pubertal estrus
• Restricting FI after achievement of puberty and
  establishment of regular estrus cycles may be
  necessary to prevent gilts from becoming too fat
  prior to breeding

83
Feeding Developing Gilts

• Nutrition Pre- and Post-Mating
• Flushing Offering elevated levels of feed 10 to
  14 d before mating to increase the number of ova
  ovulated
• Response mainly due to increased energy intake
  rather than protein
• 6 Mcal additional ME
• OR 1.8 kg of corn-SBM diet containing 3200
  kcal/kg
• OR 1.8 to 2.0 kg cereal grain as top dress to
  complete diet

84
Feeding Developing Gilts

• Nutrition Pre- and Post-Mating
• Flushing Offering elevated levels of feed 10 to
  14 d before mating to increase the number of ova
  ovulated
• Increases ovulation by 2-3 eggs
• May not increase ovulation rate over what is
  normally expected, but will correct a depression
  of ovulation rate imposed by dietary restriction
• Since most gilts are restrict fed between puberty
  and mating

85
Feeding Developing Gilts

• Nutrition Pre- and Post-Mating
• Ca and P
• Beginning at 45 kg both should be increased 0.1
  above typical GF diet to enhance skeletal
  development
• Post-mating it is critical to return gilt to
  pre-breeding energy intake
• Prevent high embryo mortality associated with
  high post-mating FI

86
The Gestating Female
87
Gestating Females

• Housing system will affect nutritional management
• Group housed sows
• Welfare friendly (? stress and ? farrowing
  process)
• Boss sow syndrome increases variability of
  weight gain and body condition
• Solution computerized feeding system
• Individually housed sows
• Increased cost and management
• Each sow can be handled differently
• Eliminates boos sow syndrome

88
Feeding Strategies

• Constant feeding level
• No flexibility to adjust nutrient intake based on
  BCS
• Phase feeding
• Adjust FI of sows to mimic nutrient needs of
  developing litter in utero
• Demands small first 2/3 of gestation and any
  changes are to improve BCS of sow
• Fetal growth rate in last trimester increases
  dramatically
• Sows may catabolize body tissues if maintained on
  a diet that satisfied their needs in early
  gestation

89
Feeding Strategies

• Phase feeding
• Caution!
• Excessive sow weight gain during gestation may
  depress FI during lactation
• Interval feeding
• Offering feed every other day (every third day,
  etc.)
• Decreases labor and management
• Works well with sows, not so well with gilts

90
Metabolic disorders of gestating females

• Due to excessive weight gain during gestation
• Gestational diabetes
• Decreases post-farrowing performance
• Low FI
• Increased body protein and fat mobilization
• Decreased milk production
• Farrowing difficulty

91
Factors affecting Nutrient Requirements

• Requirements are determined based on sow body
  weight
• Metabolic BW BW0.75
• Energy 106 ME/kg BW0.75
• Lys 36 mg/kg BW0.75
• Environmental temperature
• Above/below thermonuetral zone ? reqts.
• Lower critical temp 24C

92
Factors affecting Nutrient Requirements

• Fetal growth/maternal weight gain
• NRC presents requirements based upon anticipated
  of piglets in litter and weight gain by the sow
  during gestation
• Maintenance of sow and growth of fetus are top 2
  priorities
• However, sharp increases in energy/protein intake
  will not affect fetal size or body composition

93
Food for thought

• Too much weight gain
• Dystocia
• Poor FI and milk production
• Too little weight gain
• Inability to sustain lactation
• Delayed return to estrus and rebreeding
• Anestrus

94
The Lactating Female
95
Lactating sows

• Most challenging dietary goal of breeding herd
• Feed intake capacity during lactation to support
  nursery progeny LIMITING FACTOR to milk
  production
• 50 of preweaning deaths are related to
  insufficient milk production

96
Postfarrowing appetite depression

• Parturition is often followed by FI depression
  for several days
• Lethargy
• Limited gut capacity
• Stress of parturition
• EXCESSIVE FAT GAIN during gestation

97
Maximizing Feed Intake

• AgainPhase feeding!
• Sows are provided with gradual and restrictive
  increase in FI the first week of lactation
• Day 1 meet only maintenance reqts.
• Controlled increase will follow until d 5
• Then ad libitum access to feed for the rest of
  the lactation period

98
Milk Production

• Milk yield peaks between day 15 and 18 of
  lactation
• Milk composition can be altered by diet
• BUT, main factors affecting include
• Previous nutritional status
• Stage of production
• Diet adequacy

99
Nutrient Requirements

• 95 of total BW change in lactation is loss of
  protein and fat
• Todays females require more AA b/c they are
  producing larger litters
• However, selection for leanness and increased
  lean growth has led to reduced capacity for FI in
  sows

100
Nutrient Requirements

• Requirements determined based upon
• Sow postfarrowing weight
• Anticipated lactational weigh change
• Anticipated daily weight gain of piglets

101
Nutrient Requirements

• Requirements of AA are based on ideal protein
  concept
• Energy reqt. based upon 4 pools of need
• Maintenance (106 kcal ME/kgBW0.75)
• Milk production ((4.92litter gain)-(90
  pigs))72
• Environmental temperature (1C above/below 20C
  subtract/add 310 kcal ME)
• Energy contribution for BW loss (9.4 kcal GE/g
  fat 5.6 kcal GE/g protein assumes 1 kg BW loss
  9.42 protein)

102
Nutrient Requirements

• Mineral Nutrition
• Ca and P important for sows skeletal
  maintenance as well as for fetus development
• Ca hypocalcemia will cause poor muscle
  contraction poor milk ejection and poor uterine
  contractions during farrowing
• Mg Mg salts used as laxatives, but
  oversupplementation will result in lower Ca
  absorption

103
Nutrient Requirements

• Mineral Nutrition
• Cr positive effects on reproductive function
• 200 ppb increases litter size
• Se and Vit E deficiency will increase incidence
  of decreased milk production

104
Common feed ingredients

• Wide array can be used during gestation due to
  relatively low energy reqt. compared to other
  phases of reproductive cycle
• Energy corn, barley, wheat, and sorghum
• Protein SBM
• OR, canola meal, sunflower meal, byproducts of
  distilling industry

105
Common feed ingredients

• L-lysine used in lactation diets to meet reqt. of
  high producing sow
• WATER important to maximize milk production
• Deliver 2 L/min from nipple/cup watering systems
• FIBER used to limit energy intake of gestating
  females and functions as laxative
• ? energy intake w/o restricting total FI

106
From Weaning to Rebreeding

• Delayed return to estrus excessive BW loss
• Increased FI proven beneficial to ? wean to
  estrus interval
• BOTTOM LINE phases of reproductive cycle are
  interrelated, what you do in one phase will
  impact what occurs in the next phase.

107
Feeding Boars
108
Boar Nutrition

• Very little information
• Due to the fact that boars are a relatively small
  part of pig population
• Reproduction in a boar can be described by 3
  characteristics
• Libido of successful mountings (production of
  ejaculate)
• sperm cells
• Fertilizing capacity of sperm cells (semen
  quality)

109
Replacement Boar Nutrition

• Generally fed ad libitum during growing period
  using protein-adequate diets
• After selection period (105 kg or 5-6 mths of
  age) restricted growth is desired to prevent the
  boar from becoming too heavy to service females
• Stepwise limitation, not abrupt change

110
Replacement Boar Nutrition

• However, if protein and/or energy is restricted
  below NRC recommendation in the growing period,
  the following will be decreased
• Age at puberty
• BW at puberty
• Semen volume
• It does appear unless the males are severely
  restricted, no lasting effect on reproductive
  capacity will result

111
Adult Boar Nutrition Protein

• No positive effects of extra protein on sperm
  output or on semen quality
• Regardless of mating frequency
• In general, protein intake seems to influence
  libido and semen quantity
• i.e. Low protein (below NRC), low libido/semen
  quantity

112
Adult Boar Nutrition Energy

• Culling of boars from commercial swine herds is
  primarily because they become too heavy
• In general, reduced energy intake can negatively
  affect libido and sperm output, but semen quality
  is unaffected
• Need to feed approximately 1.5 maintenance reqt.

113
Adult Boar Nutrition Energy

• Maintenance reqt. BW0.75
• Based on sow estimate and thermonuetrality
• Boars should be given 240 kcal ME/d for every
  degree below 20C
• Growth no recommendation on ideal growth rate
• Estimated that 7.7 kcal ME/g gain
• Reproduction extra reqt. on mating day
• 4.3 kcal per kg MBW

114
Adult Boar Nutrition Vitamins and Minerals

• Vit E protects against oxidation of FA in semen
  resulting in higher semen quality
• Se deficiency results in reduced sperm and
  motility
• Ca and P no data on reproductive effects, but
  required for proper bone maintenance
• For proper libido, sound feet and legs are
  necessary
• Recommend 125-200 of NRC reqts.

115
Adult Boar Nutrition Vitamins and Minerals

• Biotin increased reqt. when foot problems
• 300 to 1000 µg/kg biotin
• Vit A 600 mg/d improves motility when semen is
  stored
• Zn
• Deficiency in young males results in lack of
  ability to attain reproductive function
• In adult males, low Zn results in reduced sperm
  quantity and quality